3GPP Working Group “SA1” defines a requirement for EPS (Evolved Packet System) to support Emergency Calls and Lawful Intercept.
Here, a “Location Reporting Procedure” used in a mobile communication system based on the UTRAN (Universal Terrestrial Radio Access Network) scheme is described with reference to FIG. 10.
As shown in FIG. 10, a core network apparatus CN is configured to transmit a “Location Reporting Control message” to a radio network controller RNC, the “Location Reporting Control message” providing an instruction to report location information on a mobile station UE performing a specific communication (for example, an emergency call or a communication targeted for lawful intercept).
Here, the radio network controller RNC is configured to report, upon receipt of the “Location Reporting Control message”, any of the following pieces of information as the location information of the mobile station UE: location information (for example, geographical information in terms of longitude information and latitude information) on a radio base station NodeB establishing a radio communication link with the mobile station UE; and identification information of a cell under control of the radio base station NodeB establishing the radio communication link with the mobile station UE.
However, the “Location Reporting Procedure” in a mobile communication system based on the conventional UMTS scheme has the following problem. Specifically, when a mobile station UE performing a specific communication performs handover (RNC relocation) from one radio network controller RNC to another, a handover target radio network controller RNC cannot take over a content of the above described “Location Reporting Control message” received by a handover source radio network controller RNC. For this reason, the core network apparatus CN needs to retransmit the same “Location Reporting Control message” to the handover target radio network controller RNC after completion of a handover procedure for this mobile station UE.